Catalyst for reductive amination reaction and use thereof

ABSTRACT

The present invention relates to a catalyst for reductive amination-reaction, and uses thereof. The catalyst according to the present invention can show a high amine conversion rate because it can maintain catalytic activity even in the presence of moisture particularly while basically maintaining the balance of dehydrogenation and hydrogenation reactions. Accordingly, the catalyst can be usefully used for preparing a polyetheramine compound through a reductive amination-reaction not only in a continuous preparation process but also in a batch preparation process, irrespective of the existence of moisture.

TECHNICAL FIELD

The present invention relates to a catalyst for reductive amination-reaction and uses thereof.

BACKGROUND OF ART

As known in the art to which the present invention pertains (hereinafter, ‘the related art’), reductive amination is one of methods for obtaining an aliphatic alkane derivative to which amine groups are introduced through a catalytic amination-reaction of the aliphatic alkane derivative under a reductive condition and in the presence of hydrogen. Such reductive amination has been used for preparing various amine compounds such as polyetheramine.

The polyetheramine compound is a compound having at least one polyoxyalkylene group, and it is being used in various ways such as a coating agent for wind power generators, an additive for epoxy coating, an additive for concrete, and the like, and it is generally prepared through reductive amination-reaction by using a compound such as a polyalkylene glycol and the like as a starting material.

In such reductive amination-reaction, a copper (Cu)-nickel (Ni) based catalyst is generally used, and there has been many attempts to increase productivity by controlling the catalytic activity by using chromium (Cr), titanium (Ti), zirconium (Zr), zinc (Zn), molybdenum (Mo), and the like as an active component.

However, the reductive amination-reaction is accompanied by the processes of dehydrogenation, dehydration, and hydrogenation, and the existing catalysts disclosed above have a problem that they lose activity easily by moisture formed during the reductive amination-reaction, or a side-reaction proceeds by the excessive moisture, and the reaction efficiency finally decreases.

To make up for this problem, a method of eliminating moisture formed during the reaction from the reaction system by carrying out the reductive amination-reaction in a continuous process has been used. However, this continuous process has a disadvantage of that complex facilities are needed and overall production efficiency decreases.

Therefore, the development of new catalyst which has a balance of dehydrogenation and hydrogenation reactions and can maintain the catalytic activity even in a batch-type process for preparing a polyetheramine compound is urgently needed.

DETAILED DESCRIPTION OF THE INVENTION Technical Problem

It is an aspect of the present invention to provide a catalyst for reductive amination-reaction which can maintain the catalytic activity and the balance of dehydrogenation and hydrogenation reactions even in the presence of moisture, and thus can show a high amine conversion rate.

It is another aspect of the present invention to provide a method of preparing a polyetheramine compound using the catalyst.

Technical Solution

According to one embodiment of the present invention, a catalyst for reductive amination-reaction including cobalt (Co) and scandium (Sc) as active components is provided.

The catalyst may include 1 to 30 parts by weight of scandium oxide, based on 100 parts by weight of cobalt oxide.

Furthermore, the catalyst may include an additional active component of one or more components selected from the group consisting of palladium, ruthenium, rhodium, and platinum.

The catalyst may include 1 to 30 parts by weight of scandium oxide, and 0.01 to 50 parts by weight of the additional active component of one or more components selected from the group consisting of palladium, ruthenium, rhodium, and platinum, based on 100 parts by weight of cobalt oxide.

The catalyst may further include a supporting material on which the active components are supported.

According to another embodiment of the present invention, a method of preparing a polyetheramine compound including a step of bringing a polyether derivative into contact with an amine compound in the presence of the catalyst disclosed above and hydrogen is provided.

Here, the step may be carried out in the presence of 0.5 to 40 parts by weight of the amine compound and 0.05 to 5 parts by weight of hydrogen, based on 100 parts by weight of the polyether derivative.

The step may be carried out at a temperature of 20° C. to 350° C. and under a pressure of 1 bar to 300 bar.

Furthermore, the polyether derivative may be a compound including 5 to 1000 carbon atoms and at least one functional group which can be substituted by an amine group.

The functional group which can be substituted by an amine group may be one or more functional groups selected from the group consisting of a hydroxyl group, an aldehyde group, a ketone group, and an imino group.

Specifically, the polyether derivative may be a compound including a repeating unit of the following Chemical Formula 1.

In Chemical Formula 1,

L¹ and L² are independently a C₁-C₁₀ alkylene, a C₂-C₁₀ alkenylene, a C₂-C₁₀ alkynylene, a C₃-C₁₀ cycloalkylene, or a C₆-C₃₀ arylene, and

n is an integer of 1 to 500.

The amine compound may be a primary amine compound or a secondary amine compound.

Advantageous Effects

The catalyst according to the present invention can show a high amine conversion rate because it can basically maintain a balance of dehydrogenation and hydrogenation reactions, and particularly, the catalytic activity can be maintained even in the presence of moisture. Accordingly, the catalyst can be useful for preparing a polyetheramine compound through reductive amination-reaction not only in a continuous preparation process, but also in a batch preparation process, irrespective of the existence of moisture.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, catalysts for reductive amination-reaction according to embodiments of the present invention and a method of preparing a polyetheramine compound using the same are explained in more detail so that a person having ordinary skill in the related art can easily make this invention. However, the present invention may be realized in many different forms and it is not limited to the examples explained in this specification.

Further, unless there is specific mention in the whole of the present specification, the technical terms used here are only for mentioning specific embodiments, and they are not intended to limit the present invention. In addition, the singular forms ‘a’, ‘an’, and ‘the’ used here include plural references unless the context clearly dictates otherwise.

In addition, the term ‘include’ used in the specification specifies specific characteristics, areas, essences, steps, motions, elements, or components, and it does not exclude the existence or addition of the other characteristics, areas, essences, steps, motions, elements, or components.

Furthermore, ‘reductive amination-reaction’ or ‘reductive amination’ in the whole of the present specification means a series of reactions for forming an aliphatic alkane derivative to which amine groups are introduced through a catalytic amination-reaction of aliphatic alkane derivatives [for example, monohydric alcohol or polyhydric alcohol, alcohol amine, and derivatives thereof (for example, epoxide, ketone, alkylene imine, and the like)] under a reductive condition and in the presence of hydrogen.

As an example of ‘reductive amination-reaction’, it may mean a series of reactions for forming an amine compound by dehydrogenating a compound including a terminal hydroxyl group so as to form an aldehyde compound, bringing the aldehyde compound into contact with a compound including an amine group so as to form an imine compound which is a reaction intermediate, and bringing the imine compound into contact with hydrogen so as to add hydrogen thereto, as in the following reaction mechanism.

[Reaction Mechanism]

Furthermore, ‘amine conversion rate’ in the whole of the specification may mean the rate or the degree of the aliphatic alkane derivative, the reactant of ‘reductive amination’, converts to the amine compound, the final product.

In the course of studying reductive amination, the present inventors recognized that when the reductive amination-reaction is carried out in the presence of the catalyst including cobalt (Co) and scandium (Sc) as active components, the catalytic activity can be maintained even in the presence of moisture, especially while properly maintaining the balance of dehydrogenation and hydrogenation reactions that come with the reaction.

The present inventors also recognized that the catalytic reduction can smoothly occur in the catalyst activation process in addition to the effects disclosed above by using the catalyst including cobalt (Co), scandium (Sc), and palladium (Pd) as active components, and completed the present invention.

According to one embodiment of the present invention, a catalyst for reductive amination-reaction including cobalt (Co) and scandium (Sc) as active components is provided.

Generally, a copper (Cu)-nickel (Ni) based catalyst, a nickel (Ni)-rhenium (Re) based catalyst, a cobalt (Co)-nickel (Ni)-copper (Cu) based catalyst, and the like have been used, and there have been many attempts to increase the catalytic activity by combining chromium (Cr), titanium (Ti), zirconium (Zr), zinc (Zn), molybdenum (Mo), and the like with the catalysts.

However, the existing catalysts disclosed above have a problem that they easily lose the activity by moisture formed during the reductive amination-reaction and the amine conversion rate rapidly decreases.

The catalyst according to one embodiment of the present invention, by comparison, includes cobalt (Co) and scandium (Sc) as active components, and it has an advantage that the catalytic activity can be maintained even in the presence of moisture, especially while properly maintaining the balance of dehydrogenation and hydrogenation reactions that come with the reductive amination.

Such phenomenon may be related to the affinity of the active components included in the catalyst. That is, the existing catalysts such as the copper (Cu)-nickel (Ni) based catalyst and the like have stronger affinity to moisture than to the amine compound and hydrogen, the reactants of the reductive amination-reaction, and thus it comes to lose the catalytic activity by the moisture formed during the reaction, and the amine conversion rate decreases rapidly.

By comparison, the catalyst according to one embodiment of the present invention can maintain the catalytic activity and shows a high amine conversion rate even though moisture is formed during the reaction, because cobalt (Co) and scandium (Sc) included in the catalyst have stronger affinity to the amine compound and hydrogen than to the moisture.

Furthermore, since the catalyst according to one embodiment of the present invention includes cobalt (Co) and scandium (Sc) as active components, it can maintain a more stable balance in dehydrogenation and hydrogenation reactions that come with the reductive amination-reaction due to their synergistic action.

According to one embodiment of the present invention, the catalyst includes cobalt (Co) and scandium (Sc) as active components, and preferably it may be a compound (CoO—Sc₂O₃) including cobalt oxide (CoO) and scandium oxide (Sc₂O₃).

The catalyst may have a composition of CoO—Sc₂O₃ after a calcination process, and may become a composition including (cobalt metal)-(scandium metal) through a catalytic reduction condition. Such oxide type or metal type of active components can be used as the catalyst in the reductive amination-reaction.

At this time, the catalyst may include 1 to 30 parts by weight of scandium oxide, preferably 1 to 25 parts by weight of scandium oxide, and more preferably 3 to 20 parts by weight of scandium oxide, based on 100 parts by weight of cobalt oxide. That is, it is advantageous to include cobalt oxide and scandium oxide in the amount disclosed above so as to realize at a least minimum effect due to the synergistic action of cobalt and scandium, by considering the degree of improvement of the catalytic activity according to the weight ratio of cobalt and scandium.

According to another embodiment of the present invention, the catalyst may further include an additional active component of one or more components selected from the group consisting of palladium (Pd), ruthenium (Ru), rhodium (Rh), and platinum (Pt).

The additional active component such as of palladium (Pd), ruthenium (Ru), rhodium (Rh), and platinum (Pt) makes the catalytic reduction occur more smoothly during the activation process of the catalyst due to the synergistic action of cobalt (Co) and scandium (Sc), and as it is hardly affected by moisture formed during the reductive amination-reaction, it can improve the amine conversion rate.

The additional active component such as palladium (Pd), ruthenium (Ru), rhodium (Rh), and platinum (Pt) may be included in a form of metal oxide in the catalyst.

Particularly, according to the present invention, the catalyst may include 1 to 30 parts by weight of scandium oxide, and 0.01 to 50 parts, preferably 0.01 to 45 parts, more preferably 0.1 to 45 parts by weight of the additional active component, based on 100 parts by weight of cobalt oxide.

That is, it is advantageous to include the active components in the amount disclosed above, by considering the degree of improvement of the catalytic activity according to their weight ratio while realizing at least minimum effect due to the synergistic action of cobalt, scandium, and the additional active component.

The catalyst for reductive amination-reaction according to the present invention may further include a supporting material.

That is, the catalyst may be a supported catalyst in which the active components including cobalt and scandium are supported on a certain supporting material, and the catalyst may further include palladium as an active component. In this way, the supported catalyst in which the active components are supported on the supporting material can secure the specific area of the active components, and an equivalent effect can be obtained even by using a relatively small quantity of the active components.

Here, any usual material known in the related art can be used as the supporting material, as long as it does not have a negative influence on the activity of the active components. According to one embodiment of the present invention, the supporting material may be SiO₂, Al₂O₃, MgO, MgCl₂, CaCl₂, ZrO₂, TiO₂, B₂O₃, CaO, ZnO, BaO, ThO₂, SiO₂—Al₂O₃, SiO₂—MgO, SiO₂—TiO₂, SiO₂—V₂O₅, SiO₂—CrO₂O₃, SiO₂—TiO₂—MgO, bauxite, zeolite, starch, cyclodextrine, or a synthetic polymer.

As a method of supporting the active components disclosed above onto the supporting material, usual supporting methods known in the related art such as a method of supporting the active components onto a dehydrated supporting material directly, a method of mixing the active components and a supporting material, supporting the active components by a precipitation method, and calcining the same, and the like may be used.

The content of the active components supported on the supporting material is not limited particularly, because it can be determined by considering the range of content which can show a minimum activity and the effect of reducing the amount of the active components according to the use of the supporting material.

The active components may be included in an amount of 1 or more parts by weight, preferably 1 to 200 parts by weight, and more preferably 10 to 150 parts by weight, based on 100 parts by weight of the supporting material. Here, the case of including 100 parts by weight of the active components based on 100 parts by weight of the supporting material can be expressed as ‘the active components are supported by 50 wt %’.

In addition, the catalyst may further include a co-catalyst compound for improving the activity of the active components disclosed above. The co-catalyst compound may be supported on the supporting material disclosed above along with the active components, and any existing co-catalyst compound known in the related art may be used without particular limitation.

Meanwhile, since the catalyst can be prepared according to a usual method known in the related art, specific features of the preparation method are also not particularly limited.

According to the present invention, the catalyst including the active components disclosed above may be prepared through a precipitation method. As an unlimited example, a catalyst according to one embodiment may be prepared by dissolving cobalt nitrate and scandium nitrate in water, adding a sodium carbonate solution thereto so as to precipitate a salt including cobalt oxide and scandium oxide, and washing, drying, and calcining the precipitated salt.

Further, a catalyst according to another embodiment may be prepared by adding an aqueous solution of palladium nitrate to the calcined catalyst prepared above and mixing the same, and drying the same at a high temperature.

Such catalyst of the present invention can be used for preparing an amine-capped aliphatic alkane derivative through the reductive amination of aliphatic alkane derivatives such as monohydric alcohol or polyhydric alcohol, alcohol amine, and derivatives thereof (for example, epoxide, ketone, alkylene imine, and the like). Preferably, the catalyst can be usefully used for preparing a polyetheramine compound through the reductive amination of a polyether derivative.

According to still another embodiment of the present invention, a method of preparing a polyetheramine compound including a step of bringing a polyether derivative into contact with an amine compound in the presence of the catalyst for reductive amination-reaction disclosed above and hydrogen is provided.

That is, according to the present invention, a method of preparing an amine-capped polyether derivative by reductive amination-reaction of a polyether derivative in the presence of the catalyst disclosed above is provided.

Particularly, as the method of preparing polyetheramine compound according to the present invention is carried out in the presence of the catalyst disclosed above, it has an advantage of that the activity of catalyst can be maintained even though water (H₂O) is formed during the reaction, and the polyetheramine compound can be prepared with a high amine conversion rate.

Accordingly, the preparation method according to the present invention can be applied not only to a continuous process but also to a batch process, and it is possible to prepare the polyetheramine compound by using more simplified production facilities. Furthermore, the preparation method can provide high selectivity for the primary amine compound which is industrially more useful.

According to the present invention, the preparation method can be carried out through a series of reactions including a reaction for forming an aldehyde compound by dehydrogenating the polyether derivative, a reaction for forming an imine compound by bringing the aldehyde compound into contact with an amine compound, and a hydrogenating reaction by bringing the imine compound into contact with hydrogen.

In the preparation method, each reaction disclosed above may be carried out separately or may be carried out through a series of continuous reactions undifferentiated in process condition and process efficiency. That is, the preparation method may be carried out through a series of reductive amination-reactions which bring a polyether derivative into contact with an amine compound in the presence of the catalyst disclosed above and hydrogen.

In the present invention, a preferable material (i.e., a reactant) for the reductive amination using the catalyst disclosed above is a polyether derivative, and it can finally provide a compound capped by at least one amine group (i.e., a polyetheramine compound).

Specifically, the polyether derivative may be a polyether based compound having at least one functional group which can be substituted by an amine group, and it may preferably be a compound including 5 to 1000 carbon atoms.

Here, the functional group which can be substituted by the amine group may be one or more functional groups selected from the group consisting of a hydroxyl group, an aldehyde group, a ketone group, and an imino group.

Therefore, in the embodiment of the present invention, any polyether derivative satisfying the conditions disclosed above can be used as the reactant without particular limitation. However, preferably, the polyether derivative may be a compound including a functional group which can be substituted by the amine group, and a repeating unit of Chemical Formula 1.

In Chemical Formula 1,

L¹ and L² are independently a C₁-C₁₀ alkylene, a C₂-C₁₀ alkenylene, a C₂-C₁₀ alkynylene, a C₃-C₁₀ cycloalkylene, or a C₆-C₃₀ arylene, and

n is an integer of 1 to 500.

Here, the ‘alkylene’ means a secondary functional group derived from a linear or branched alkane; ‘alkenylene’ means a secondary functional group derived from a linear or branched alkene; ‘alkynylene’ means a secondary functional group derived from a linear or branched alkyne; tycloalkylene′ means a secondary functional group derived from a cycloalkane; and ‘arylene’ means a secondary functional group derived from an arene.

According to one embodiment of the present invention, the polyether derivative may be an alcohol (ethyl alcohol, propyl alcohol, butyl alcohol, aliphatic alcohol, alkylphenyl alcohol, and the like) including the repeating unit of Chemical Formula 1, a glycol (polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, and the like) including the repeating unit of Chemical Formula 1, a triol including the repeating unit of Chemical Formula 1, an aldehyde compound including the repeating unit of Chemical Formula 1, a ketone compound including the repeating unit of Chemical Formula 1, or an imino compound including the repeating unit of Chemical Formula 1.

The compound including the repeating unit of Chemical Formula 1 may be a block polymer or a random polymer including the repeating unit. For example, the polyether derivative may include a copolymer such as polypropylene glycol-polyethylene glycol-polypropylene glycol and the like.

According to another embodiment of the present invention, the polyether derivative may be a polyoxyalkylene compound represented by the following Chemical Formula 2.

In Chemical Formula 2,

L¹ and L² are independently a C₁-C₁₀ alkylene, a C₂-C₁₀ alkenylene, a C₂-C₁₀ alkynylene, a C₃-C₁₀ cycloalkylene, or a C₆-C₃₀ arylene,

R¹ is hydrogen, a C₁-C₁₈ alkyl group, an unsubstituted C₆-C₃₀ aryl group, or a C₆-C₃₀ aryl group substituted by a C₁-C₁₈ alkyl group, and

n is an integer of 1 to 500.

According to still another embodiment of the present invention, the polyether derivative may be a polyoxyalkylene compound represented by the following Chemical Formula 3.

In Chemical Formula 3,

L³ to L⁶ are independently a C₁-C₁₀ alkylene, a C₂-C₁₀ alkenylene, a C₂-C₁₀ alkynylene, a C₃-C₁₀ cycloalkylene, or a C₆-C₃₀ arylene,

R² is hydrogen, a C₁-C₁₈ alkyl group, an unsubstituted C₆-C₃₀ aryl group, or a C₆-C₃₀ aryl group substituted by a C₁-C₁₈ alkyl group, and

a and b are independently an integer of 1 to 500.

According to still another embodiment of the present invention, the polyether derivative may be a polyoxyalkylene compound represented by the following Chemical Formula 4.

In Chemical Formula 4,

L⁷ to L¹² are independently a C₁-C₁₀ alkylene, a C₂-C₁₀ alkenylene, a C₂-C₁₀ alkynylene, a C₃-C₁₀ cycloalkylene, or a C₆-C₃₀ arylene,

R³ is hydrogen, a C₁-C₁₈ alkyl group, an unsubstituted C₆-C₃₀ aryl group, or a C₆-C₃₀ aryl group substituted by a C₁-C₁₈ alkyl group,

y is an integer of 2 to 500, and

(x+z) is an integer of 2 to 100.

The compounds of Chemical Formula 2 to Chemical Formula 4 disclosed above are polyoxyalkylene compounds including at least one hydroxyl end group, and they can be used as examples of the reactant in the reductive amination-reaction according to the present invention.

In the method of preparing the polyetheramine compound according to the present invention, the polyether derivative reacts with one or more amine compounds.

As the amine compound, usual compounds including an amine group may be used without particular limitation, and preferably, a primary amine compound or a secondary amine compound may be used.

More preferably, the amine compound may be one or more compounds selected from the group consisting of ammonia, methylamine, ethylamine, propylamine, butylamine, ethylenediamine, aniline, piperazine, aminoethylpiperazine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, diethylamine, dipropylamine, dibutylamine, isopropylamine, diisopropylamine, diisopropanolamine, ethanolamine, diethanolamine, and diisobutyleneamine.

In the step of bringing the polyether derivative into contact with the amine compound, the weight ratio of the reactant is not limited particularly because it can be determined within the range in which a series of reactions can be carried out sufficiently by considering the reaction efficiency.

According to the present invention, however, it may be advantageous in terms of the improvement of the reaction efficiency that the step is carried out in the presence of 0.5 to 40 parts by weight, preferably 1 to 40 parts by weight, more preferably 1 to 35 parts by weight of the amine compound, and 0.05 to 5 parts by weight, preferably 0.1 to 3 parts by weight, more preferably 0.1 to 2 parts by weight of hydrogen, based on 100 parts by weight of the polyether derivative.

It may be advantageous in terms of the improvement of the reaction efficiency that the step is carried out at a temperature of 20° C. to 350° C. and under the pressure of 1 bar to 300 bar, preferably at a temperature of 20° C. to 300° C. and under the pressure of 1 bar to 250 bar, and more preferably at a temperature of 20° C. to 250° C. and under the pressure of 1 bar to 220 bar.

In addition to the steps disclosed above, the preparation method of polyetheramine compound according to the present invention may further include a usual step known in the related art before or after each step disclosed above.

Hereinafter, preferable examples are provided for understanding the present invention. However, the following examples are only for illustrating the present invention, and the present invention is not limited to or by them.

First, the catalysts of examples and comparative examples were prepared by the following methods (Examples 1-6 and Comparative Examples 1-2), and the polyetheramine compounds were prepared by using each catalyst (Preparation Examples 1-6 and Comparative Preparation Examples 1-2).

The results of the examples and comparative examples are summarized in the following Table 1.

At this time, ‘amine conversion rate’ means the rate (weight ratio) at which the polyether derivative of the starting material is converted into the polyetheramine compound, and the weight of the polyetheramine compound was measured by the titration method according to total amine value measurement (ASTM D2074).

Further, ‘primary amine selectivity’ means the rate (weight ratio) of the primary amine compound in the product, and it was measured by the titration method according to primary amine value measurement (ASTM D2074).

Example 1 Preparation of CoO—Sc₂O₃ Catalyst

At room temperature, about 44.034 g of cobalt nitrate and about 0.349 g of scandium nitrate were dissolved in about 400 g of water, and the precipitation method was carried out by injecting a 15 wt % aqueous solution of sodium carbonate at a speed of about 0.08 ml/s.

After about 1 h passed, the formed salt was washed and filtered numerous times by using about 500 ml of distilled water, and it was dried at about 110° C. for about 15 h.

The CoO—Sc₂O₃ catalyst (including about 3.55 parts by weight of Sc₂O₃, based on 100 parts by weight of CoO) was obtained by the method of putting the salt dried as above into a furnace and raising the furnace temperature up to about 600° C. with a heating rate of about 300° C./h, and calcining the salt for about 4 h at about 600° C. under ambient atmosphere.

Example 2 Preparation of CoO—Sc₂O₃—PdO Catalyst

At room temperature, about 44.034 g of cobalt nitrate and about 0.349 g of scandium nitrate were dissolved in about 400 g of water, and the precipitation method was carried out by injecting a 15 wt % aqueous solution of sodium carbonate at a speed of about 0.08 ml/s.

After about 1 h passed, the formed salt was washed and filtered numerous times by using about 500 ml of distilled water, and it was dried at about 110° C. for about 15 h.

The salt dried as above was put into a furnace, and calcined for about 4 h at about 600° C. under ambient atmosphere after raising the furnace temperature up to about 600° C. at a heating rate of about 300° C./h.

The CoO—Sc₂O₃—PdO catalyst (including about 3.55 parts by weight of Sc₂O₃ and about 0.13 parts by weight of PdO based on 100 parts by weight of CoO) was obtained by the method of adding 20 ml of an aqueous solution in which about 0.028 g of palladium nitrate was dissolved with the calcined salt and mixing them together, and drying the same at about 110° C. for about 15 h.

Example 3 Preparation of CoO—Sc₂O₃—PdO Catalyst

At room temperature, about 44.034 g of cobalt nitrate and about 0.349 g of scandium nitrate were dissolved in about 400 g of water, and the precipitation method was carried out by injecting a 15 wt % aqueous solution of sodium carbonate at a speed of about 0.08 ml/s.

After about 1 h passed, the formed salt was washed and filtered numerous times by using about 500 ml of distilled water, and it was dried at about 110° C. for about 15 h.

The salt dried as above was put into a furnace, and calcined for about 4 h at about 600° C. under ambient atmosphere after raising the furnace temperature up to about 600° C. at a heating rate of about 300° C./h.

The CoO—Sc₂O₃—PdO catalyst (including about 3.55 parts by weight of Sc₂O₃ and about 0.26 parts by weight of PdO based on 100 parts by weight of CoO) was obtained by the method of adding 20 ml of an aqueous solution in which about 0.056 g of palladium nitrate was dissolved with the calcined salt and mixing them together, and drying the same at about 110° C. for about 15 h.

Example 4 Preparation of CoO—Sc₂O₃—PdO Supported Catalyst

At room temperature, about 30.019 g of cobalt nitrate and about 0.238 g of scandium nitrate were dissolved in about 200 g of water, about 100 g of water including about 8 g of Al₂O₃ (produced by Aldrich) as a supporting material was added thereto, and the precipitation method was carried out by injecting a 15 wt % aqueous solution of sodium carbonate at a speed of about 0.08 ml/s.

After about 1 h passed, the formed salt was washed and filtered numerous times by using about 500 ml of distilled water, and it was dried at about 110° C. for about 15 h.

The salt dried as above was put into a furnace, and calcined for about 4 h at about 600° C. under ambient atmosphere after raising the furnace temperature up to about 600° C. at a heating rate of about 300° C./h.

The (CoO—Sc₂O₃—PdO)/Al₂O₃ supported catalyst (supported by 50 wt % of the active components, including about 3.55 parts by weight of Sc₂O₃ and about 0.13 parts by weight of PdO, based on 100 parts by weight of CoO) was obtained by the method of adding 20 ml of an aqueous solution in which about 0.019 g of palladium nitrate was dissolved with the calcined salt and mixing together, and drying the same at about 110° C. for about 15 h.

Example 5 Preparation of CoO—Sc₂O₃—PdO Supported Catalyst

The (CoO—Sc₂O₃—PdO)/(SiO₂—Al₂O₃) supported catalyst was obtained, except that SiO₂—Al₂O₃ as a supporting material was used instead of Al₂O₃ by the same method as Example 4.

Example 6 Preparation of CoO—Sc₂O₃—PdO Supported Catalyst

The (CoO—Sc₂O₃—PdO)/(2MgO-6SiO₂-xH₂O) supported catalyst was obtained, except that 2MgO-6SiO₂-xH₂O (produced by Kyowa Chemical Industry Co., Ltd., product name: KW600) as a supporting material was used instead of Al₂O₃ by the same method as Example 4.

Comparative Example 1 Preparation of CoO Catalyst

At room temperature, about 44.034 g of cobalt nitrate was dissolved in about 400 g of water, and the precipitation method was carried out by injecting a 15 wt % aqueous solution of sodium carbonate at a speed of about 0.08 ml/s.

After about 1 h passed, the formed salt was washed and filtered numerous times by using about 500 ml of distilled water, and it was dried at about 110° C. for about 15 h.

The CoO catalyst was obtained by the method of putting the salt dried as above into a furnace, raising the furnace temperature up to about 600° C. at a heating rate of about 300° C./h, and calcining the salt for about 4 h at about 600° C. under ambient atmosphere.

Comparative Example 2 Preparation of (CuO—NiO)/Al₂O₃ Catalyst

At room temperature, about 9.437 g of copper nitrate and about 3.893 g of nickel nitrate were dissolved in about 400 g of water, and about 5 g of aluminum oxide (Al₂O₃) was added therein. The precipitation method was carried out by injecting a 15 wt % aqueous solution of sodium carbonate at a speed of about 0.03 ml/s.

After about 1 h passed, the formed salt was washed and filtered numerous times by using about 500 ml of distilled water, and it was dried at about 110° C. for about 15 h.

The (CuO—NiO)/Al₂O₃ catalyst (including about 20 parts by weight of NiO, based on 100 parts by weight of CuO) was obtained by the method of putting the salt dried as above into a furnace, raising the furnace temperature up to about 450° C. at a heating rate of about 300° C./h, and calcining the salt for about 4 h at about 450° C. under ambient atmosphere.

Preparation Example 1 Preparation of Polyetheramine Compound

About 3.5 g of the catalyst according to Example 1 (CoO—Sc₂O₃ catalyst) and about 70 g of polypropylene glycol (produced by Aldrich, product name: PPG-1000, number average molecular weight (Mn): about 1000) represented by the following chemical formula were put into a batch type reactor of a 200 ml capacity.

Subsequently, oxygen in the reactor was eliminated by nitrogen purge5 times, and hydrogen at about 50 bar was injected therein at room temperature. Then, the catalyst activation was carried out for about 1 h after raising the temperature of the reactor up to about 250° C., and subsequently hydrogen in the reactor was vented out after cooling the temperature of the reactor to about 80° C.

After cooling the temperature of the reactor to about 40° C., about 23.8 g of ammonia at about −20° C. was injected in company with hydrogen so as to make the pressure in the reactor be 50 bar (about 34.0 parts by weight of ammonia and about 0.7 parts by weight of hydrogen, based on 100 parts by weight of PPG-1000).

Thereafter, about 28.14 g of the polyetheramine compound (amine conversion rate: about 40.2%) was obtained by the method of raising the temperature of the reactor up to 220° C. and reacting the contents under the pressure of about 200 bar for about 5 h.

Preparation Example 2 Preparation of Polyetheramine Compound

About 63.8 g of the polyetheramine compound (amine conversion rate: about 91.2%) was obtained, except that the catalyst of Example 2 (CoO—Sc₂O₃—PdO catalyst) was used instead of the catalyst of Example 1 by the same method as Preparation Example 1.

Preparation Example 3 Preparation of Polyetheramine Compound

About 64.68 g of the polyetheramine compound (amine conversion rate: about 92.4%) was obtained, except that the catalyst of Example 3 (CoO—Sc₂O₃—PdO catalyst) was used instead of the catalyst of Example 1 by the same method as Preparation Example 1.

Preparation Example 4 Preparation of Polyetheramine Compound

About 69.4 g of the polyetheramine compound (amine conversion rate: about 99.2%) was obtained, except that the catalyst of Example 4 [(CoO—Sc₂O₃—PdO)/Al₂O₃ supported catalyst] was used instead of the catalyst of Example 1 by the same method as Preparation Example 1.

Preparation Example 5 Preparation of Polyetheramine Compound

About 69.7 g of the polyetheramine compound (amine conversion rate: about 99.5%) was obtained, except that the catalyst of Example 5 [(CoO—Sc₂O₃—PdO)/(SiO₂—Al₂O₃) supported catalyst] was used instead of the catalyst of Example 1 by the same method as Preparation Example 1.

Preparation Example 6 Preparation of Polyetheramine Compound

About 69.3 g of the polyetheramine compound (amine conversion rate: about 99.0%) was obtained, except that the catalyst of Example 6 [(CoO—Sc₂O₃—PdO)/(2MgO-6SiO₂-xH₂O) supported catalyst] was used instead of the catalyst of Example 1 by the same method as Preparation Example 1.

Comparative Preparation Example 1 Preparation of Polyetheramine Compound

About 10.64 g of the polyetheramine compound (amine conversion rate: about 15.2%) was obtained, except that the catalyst of Comparative Example 1 (CoO catalyst) was used instead of the catalyst of Example 1 by the same method as Preparation Example 1.

Comparative Preparation Example 2 Preparation of Polyetheramine Compound

About 4.12 g of the polyetheramine compound (amine conversion rate: about 5.9%) was obtained, except that the catalyst of Comparative Example 2 [(CuO—NiO)/Al₂O₃ catalyst] was used instead of the catalyst of Example 1 by the same method as Preparation Example 1.

TABLE 1 Amine conversion Catalyst rate (%) Preparation Example 1 40.2 Example 1 (CoO—Sc₂O₃) Preparation Example 2 91.2 Example 2 (CoO—Sc₂O₃—PdO; PdO 0.13 PBW*) Preparation Example 3 92.4 Example 3 (CoO—Sc₂O₃—PdO; PdO 0.26 PBW) Preparation Example 4 99.2 Example 4 (CoO—Sc₂O₃—PdO; Al₂O₃ supported) Preparation Example 5 99.5 Example 5 (CoO—Sc₂O₃—PdO; SiO₂—Al₂O₃ supported) Preparation Example 6 99.0 Example 6 (CoO—Sc₂O₃—PdO; 2MgO—6SiO₂—xH₂O supported) Comparative Comparative Example 1 15.2 Preparation (CoO) Example 1 Comparative Comparative Example 2 5.9 Preparation (CuO—NiO; Al₂O₃ supported) Example 2 *PBW: parts by weight

As shown in Table 1, the Preparation Examples 1 to 6 using the catalysts of Examples 1 to 6 show significantly higher amine conversion rates compared to the Comparative Preparation Examples 1 and 2.

Further, it is recognized that the supported catalyst including the supporting material like Preparation Examples 4 to 6 can show the amine conversion rate being equivalent to other examples, even though the content of the active components are decreased to nearly half.

In comparison, the Comparative Preparation Examples 1 and 2 using the catalysts of Comparative Examples 1 and 2 show low amine conversion rates of below 20%. That is, it is recognized that the existing catalysts like Comparative Examples 1 and 2 rapidly decrease in catalytic activity if there is moisture in the reactor and overall efficiency of the amination-reaction decreases. 

1. A catalyst for reductive amination-reaction, including cobalt and scandium as active components.
 2. The catalyst according to claim 1, including 1 to 30 parts by weight of scandium oxide, based on 100 parts by weight of cobalt oxide.
 3. The catalyst according to claim 1, further including a supporting material on which the active components are supported.
 4. The catalyst according to claim 1, further including an additional active component of or more components selected from the group consisting of palladium, ruthenium, rhodium, and platinum.
 5. The catalyst according to claim 4, including 1 to 30 parts by weight of scandium oxide and 0.01 to 50 parts by weight of the additional active component of one or more components selected from the group consisting of palladium, ruthenium, rhodium, and platinum, based on 100 parts by weight of cobalt oxide.
 6. The catalyst according to claim 4, further including a supporting material on which the active components are supported.
 7. A method of preparing a polyetheramine compound, including a step of bringing a polyether derivative into contact with an amine compound, in the presence of the catalyst for reductive amination-reaction according to claim 1 and hydrogen.
 8. The method according to claim 7, wherein the step is carried out in the presence of 0.5 to 40 parts by weight of an amine compound and 0.05 to 5 parts by weight of hydrogen, based on 100 parts by weight of a polyether derivative.
 9. The method according to claim 7, wherein the step is carried out at a temperature of 20° C. to 350° C. and under a pressure of 1 bar to 300 bar.
 10. The method according to claim 7, wherein the polyether derivative is a compound including 5 to 1000 carbon atoms and at least one functional group which can be substituted by an amine group.
 11. The method according to claim 10, wherein the functional group which can be substituted by an amine group is one or more functional groups selected from the group consisting of a hydroxyl group, an aldehyde group, a ketone group, and an imino group.
 12. The method according to claim 10, wherein the polyether derivative is a compound including a repeating unit of the following Chemical Formula 1:

wherein, in Chemical Formula 1, L¹ and L² are independently a C₁-C₁₀ alkylene, a C₂-C₁₀ alkenylene, a C₂-C₁₀ alkynylene, a C₃-C₁₀ cycloalkylene, or a C₆-C₃₀ arylene, and n is an integer of 1 to
 500. 13. The method according to claim 7, wherein the polyether derivative is a polyoxyalkylene compound represented by the following Chemical Formula 2:

wherein, in Chemical Formula 2, L¹ and L² are independently a C₁-C₁₀ alkylene, a C₂-C₁₀ alkenylene, a C₂-C₁₀ alkynylene, a C₃-C₁₀ cycloalkylene, or a C₆-C₃₀ arylene, R¹ is hydrogen, a C₁-C₁₈ alkyl group, an unsubstituted C₆-C₃₀ aryl group, or a C₆—O₃₀ aryl group substituted by a C₁-C₁₈ alkyl group, and n is an integer of 1 to
 500. 14. The method according to claim 7, wherein the polyether derivative is a polyoxyalkylene compound represented by the following Chemical Formula 3:

wherein, in Chemical Formula 3, L³ to L⁶ are independently a C₁-C₁₀ alkylene, a C₂-C₁₀ alkenylene, a C₂-C₁₀ alkynylene, a C₃-C₁₀ cycloalkylene, or a C₆-C₃₀ arylene, R² is hydrogen, a C₁-C₁₈ alkyl group, an unsubstituted C₆-C₃₀ aryl group, or a C₆-C₃₀ aryl group substituted by a C₁-C₁₈ alkyl group, and a and b are independently an integer of 1 to
 500. 15. The method according to claim 7, wherein the polyether derivative is a polyoxyalkylene compound represented by the following Chemical Formula 4:

wherein, in Chemical Formula 4, L⁷ to L¹² are independently a C₁-C₁₀ alkylene, a C₂-C₁₀ alkenylene, a C₂-C₁₀ alkynylene, a C₃-C₁₀ cycloalkylene, or a C₆-C₃₀ arylene, R³ is hydrogen, a C₁-C₁₈ alkyl group, an unsubstituted C₆-C₃₀ aryl group, or a C₆-C₃₀ aryl group substituted by a C₁-C₁₈ alkyl group, y is an integer of 2 to 500, and (x+z) is an integer of 2 to
 100. 16. The method according to claim 7, wherein the amine compound is a primary amine compound or a secondary amine compound.
 17. The method according to claim 7, wherein the amine compound is one or more compounds selected from the group consisting of ammonia, methylamine, ethylamine, propylamine, butylamine, ethylenediamine, aniline, piperazine, aminoethylpiperazine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, diethylamine, dipropylamine, dibutylamine, isopropylamine, diisopropylamine, diisopropanolamine, ethanolamine, diethanolamine, and diisobutyleneamine. 